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authorFlorian Weimer <fweimer@redhat.com>2021-10-01 18:16:41 +0200
committerFlorian Weimer <fweimer@redhat.com>2021-10-01 18:16:41 +0200
commiteae81d70574e923ce3c59078b8df857ae192efa6 (patch)
tree7e7ed9a2ae46d5f6e8129871949d23a750fdced2 /sysdeps/pthread
parent176c88f5214d8107d330971cbbfbbba5186a111f (diff)
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nptl: pthread_kill must send signals to a specific thread [BZ #28407]
The choice between the kill vs tgkill system calls is not just about the TID reuse race, but also about whether the signal is sent to the whole process (and any thread in it) or to a specific thread. This was caught by the openposix test suite: LTP: openposix test suite - FAIL: SIGUSR1 is member of new thread pendingset. <https://gitlab.com/cki-project/kernel-tests/-/issues/764> Fixes commit 526c3cf11ee9367344b6b15d669e4c3cb461a2be ("nptl: Fix race between pthread_kill and thread exit (bug 12889)"). Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
Diffstat (limited to 'sysdeps/pthread')
-rw-r--r--sysdeps/pthread/Makefile1
-rw-r--r--sysdeps/pthread/tst-pthread-raise-blocked-self.c92
2 files changed, 93 insertions, 0 deletions
diff --git a/sysdeps/pthread/Makefile b/sysdeps/pthread/Makefile
index d4bd2d4e3e..0af9c59b42 100644
--- a/sysdeps/pthread/Makefile
+++ b/sysdeps/pthread/Makefile
@@ -121,6 +121,7 @@ tests += tst-cnd-basic tst-mtx-trylock tst-cnd-broadcast \
tst-pthread-setuid-loop \
tst-pthread_cancel-exited \
tst-pthread_cancel-select-loop \
+ tst-pthread-raise-blocked-self \
tst-pthread_kill-exited \
tst-pthread_kill-exiting \
# tests
diff --git a/sysdeps/pthread/tst-pthread-raise-blocked-self.c b/sysdeps/pthread/tst-pthread-raise-blocked-self.c
new file mode 100644
index 0000000000..128e1a6071
--- /dev/null
+++ b/sysdeps/pthread/tst-pthread-raise-blocked-self.c
@@ -0,0 +1,92 @@
+/* Test that raise sends signal to current thread even if blocked.
+ Copyright (C) 2021 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <signal.h>
+#include <support/check.h>
+#include <support/xsignal.h>
+#include <support/xthread.h>
+#include <pthread.h>
+#include <unistd.h>
+
+/* Used to create a dummy thread ID distinct from all other thread
+ IDs. */
+static void *
+noop (void *ignored)
+{
+ return NULL;
+}
+
+static volatile pthread_t signal_thread;
+
+static void
+signal_handler (int signo)
+{
+ signal_thread = pthread_self ();
+}
+
+/* Used to ensure that waiting_thread has launched and can accept
+ signals. */
+static pthread_barrier_t barrier;
+
+static void *
+waiting_thread (void *ignored)
+{
+ xpthread_barrier_wait (&barrier);
+ pause ();
+ return NULL;
+}
+
+static int
+do_test (void)
+{
+ xsignal (SIGUSR1, signal_handler);
+ xpthread_barrier_init (&barrier, NULL, 2);
+
+ /* Distinct thread ID value to */
+ pthread_t dummy = xpthread_create (NULL, noop, NULL);
+ signal_thread = dummy;
+
+ pthread_t helper = xpthread_create (NULL, waiting_thread, NULL);
+
+ /* Make sure that the thread is running. */
+ xpthread_barrier_wait (&barrier);
+
+ /* Block signals on this thread. */
+ sigset_t set;
+ sigfillset (&set);
+ xpthread_sigmask (SIG_BLOCK, &set, NULL);
+
+ /* Send the signal to this thread. It must not be delivered. */
+ raise (SIGUSR1);
+ TEST_VERIFY (signal_thread == dummy);
+
+ /* Wait a bit to give a chance for signal delivery (increases
+ chances of failure with bug 28407). */
+ usleep (50 * 1000);
+
+ /* Unblocking should cause synchronous delivery of the signal. */
+ xpthread_sigmask (SIG_UNBLOCK, &set, NULL);
+ TEST_VERIFY (signal_thread == pthread_self ());
+
+ xpthread_cancel (helper);
+ xpthread_join (helper);
+ xpthread_join (dummy);
+ return 0;
+}
+
+#include <support/test-driver.c>